"Richard Clark" wrote in message
...
On Thu, 28 May 2009 22:30:20 +0100, Ian Jackson
wrote:

What 'vanity' does a J-pole serve? It's a simple,

Simple compared to something even more elaborate (11 out of 10), I
suppose, which would be more vainglorious.

efficient,

More efficient than a rubber ducky was allowed (the need for that
efficiency has been skirted, however), so the claim of efficiency
appeals to vanity when the difference was already noted. More
efficient than a rubber ducky giving full quietening? What does that
matter if not to suit vanity?

endfed
halfwave (essentially a 'Zepp')

Now there's vanity in its full glory with the trappings of provenance
(the hushed heritage of the era of the romantic Zeppelins). I bet
tagging it with the name Zepp adds 5dBd gain alone!

, low angle radiation,

Any lower angle than a rubber ducky? It is vanity to sneer at the
ducky, especially when it gets the job done without all this pomp and
circumstance.

easy to construct,

I presume this the vain form of "simple."

tune up, and mount on the top of a pole.

You can mount a rubber ducky on the top of a pole too, but suffer the
humiliation. No vanity boost in doing that, of course; so guilt
demands a J-pole.

I see no 'vanity'.

I can't either - not here in the basement where I can hit my buddy's
repeater a dozen miles away with a 1/2W HT driving a 6" whip. Note I
say that I "can," but I don't for the shame of not having a J-pole
mounted on a 20 foot mast. I only kerchunk it knowing full well my
buddies won't talk to me on my whip through their own J-Poles. Of
course this is ironic where the repeater is using a quarterwave
because it is:
1. Much simpler,
2. Vastly more efficient;
3. Has an immensely lower angle of radiation;
4. Is superior to tune up;
5. and is mounted on a really, really tall tower (not a pole).

73's
Richard Clark, KB7QHC

The 1/4 wave ground plane has a useless pattern. Main lobe at about 30
degrees above horizon, but broad enough to be usable and simple to build. I
have one as a receive antenna for duplex operation, shielded from the
transmit antennas by an air conditioner and vertical separation, feeding
several receivers with cavities. It is literally thrown on the roof and
coax is routed through the ductwork. Hasn't moved for 12 years. Hint: if
you use an SO-239, seal the center conductor so water wont run down the rod
and into the connector. Tape the coax connector tightly.

For frequencies below 220, it is best to put up an outside antenna. Above
those frequencies, RF gets out with much less shielding from the building.

J-poles, vertical dipoles have a more useful pattern below horizon. They
provide useful performance without being too large. The typical 2 meter
rubber ducky has anywhere from 6 to 20 db of loss. The typical 2m 5/8 and
5db 440 dual band mobile antenna will be noticeably better.

What's with all the EMO girl chatter?